In modern society, use of electronic products has become an indispensable part in life, and almost everything, such as food, clothing, living, transport, education, and entertainment, is related to the electronic products. Generally, a consumer electronic product is provided with a keyboard. To increase the practicability of the keyboard, a backlight module is usually disposed inside the keyboard, and the backlight module can project generated light rays to key caps of the keyboard, to enable a user to operate the keyboard in a dimly lit environment. On the other hand, the backlight module can also be used to implement a keyboard prompting function.
In existing keyboard backlight technologies, a layer of a light guide plate structure may be disposed below a support plate of a keyboard, and corresponding light transmitting holes are disposed at positions of keys. In this way, light rays in the light guide plate may be obtained through the light transmitting holes and further projected to key caps of the keyboard, so that the keyboard produces an obvious highlight display effect. Alternatively, one or more light emitting components may be disposed in a particular area below a keyboard, and the light emitting component directly projects generated light rays to key caps of the keyboard. In the conventional technology, light emitting components are mainly light emitting diodes (LEDs). Because most of light rays emitted from an LED are concentrated around an optical axis, the LED is usually considered to be a point light source. However, when an LED is at a short distance from a key cap, because light rays emitted from the LED are excessively concentrated, the light rays emitted from the LED cannot be effectively spread to the entire key cap. Consequently, a phenomenon of the uneven brightness occurs on a surface of the key cap. Further, if light rays emitted from an LED are excessively strong, a notable bright spot may be generated on a surface of a key cap, making it difficult for a user to recognize a character symbol of the key cap, leading to inconvenience in use.
Therefore, how to improve the brightness of light emission, the irradiation angle, and the evenness of light emergence of a light emitting module is a technical problem to be resolved by the present invention.